PixelAndPolygon

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Pico Pixel 0.6.5 has been released. As I mentionned in a previously blog post, there is partial support for PVR texture files. Although support for more format in PVR files will improve in subsequent releases, head over to Pico Pixel Support and let us know if you need to prioritize support for a specific texture format.

Also making a debut in Pico Pixel 0.6.5 is the texel grid. The grid shows up one texel have a size greater than 5x5. Use the 9 key to turn the grid on or off.

Cut off from this release is support for alternative view of 2D and volume textures. Alternative view for 2D textures would show all the mip levels (if any) at the same time.

For volume textures, the alternate view shows the depth textures spreaded out in a row.

Alternative views for cubemaps is still supported and are accessed by pressing the Enter key.

Pico Pixel 0.6.5 will have a grid to isolate individual texels in textures. The grid can be turned on and off and only shows up once texels reach a size of 5x5 pixels on screen.

Rather than a grid made of straight lines going from top to bottom and from left to right, the grid places two small crossing lines (at 90 degrees) at the the corners of texels. The result is rather neat.

OpenGL extension GL_ARB_draw_instanced is used to optimize the rendering of the grid.

I was pretty confident of the support for KTX files in Pico Pixel. However, this being a new file format, there aren’t many references viewer for it. The only one I found is Mali GPU Texture Compression Tool.

It turns out Mali’s tool does not correctly reproduce the mipmaps of texture it generates. While the Mali’s texture compression works, the reproduction of the rendering in the tool’s interface is wrong. Unfortunately, Pico Pixel also had the same issue.

In all the pictures, both Pico Pixel and Mali’s tool are using texture rgb-mipmap-reference.ktx from Khronos KTX SDK.

This is what Mali’s tool (v4.1) shows.

Prior to release 0.6.2, Pico Pixel showed the same mipmap chain except for the last mip (level 6). Indeed, after a long investigation at the time, I came with the conclusion that level 6 in Mali’s tool was wrong and the last mip level should be pink (0, FF, FF) instead of black.

Still, Pico Pixel had level 5 wrong just like Mali’s tool.

Thanks to a bug report, this problem is fixed in 0.6.2. Here is what Pico Pixel shows now.

A bug has also been submitted for the problem in Mali’s tool but I don’t know when it is going to be addressed.